<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var str = 'I Love You';
        // 不要想的太复杂
        //结果要求uoY evoL I
        var a = str.split("").reverse().join("");
        console.log(a);
    </script>
</body>
</html>